Diagn Interv Radiol 2008; 14:205–211 ABDOMINAL IMAGING © Turkish Society of Radiology 2008 ORIGINAL ARTICLE Does an extra kidney-ureter-bladder radiograph taken in the upright position during routine intravenous urography provide diagnostic benefit? Kamil Gürel, Safiye Gürel, Melike Kalfaoğlu, Özlem Yılmaz, Ahmet Metin PURPOSE ntravenous urography (IVU) has long been the main imaging method The aim of this prospective study was to assess the for evaluation of urinary tract disease. However, other imaging modali- diagnostic benefit of taking a kidney-ureter-bladder ties including ultrasonography, computed tomography (CT), and mag- (KUB) radiograph in an upright position during rou- I tine intravenous urography (IVU). netic resonance imaging (MRI) have been used with increasing frequency to compensate for the limitations of IVU in the evaluation of urinary tract MATERIALS AND METHODS Between February 2005 and September 2007, 170 disease; in the last two decades, use of these modalities has surpassed use consecutive patients were included in the study. A of the IVU (1). Recently the IVU has almost been regarded as outdated, basal IVU exam consisted of pre-contrast supine KUB, and an “epitaph for the urogram” has been prepared (2). Despite the in- post-contrast supine KUB at the 7th and 15th min- utes, and supine pelvic radiographs with full bladder creased use of alternative modalities, each has limitations. The ideal “glo- and post-voiding. When needed, additional compres- bal” urinary tract examination remains controversial (1, 3, 4). sion and/or oblique radiographs were taken. In this study, for all patients, a post-contrast 15th minute The IVU remains an appropriate examination for untangling compli- upright KUB radiograph was added to IVU. Two con- cated congenital anomalies, demonstrating surgical reconstructions of secutive radiographs taken at the 15th minute post- urinary tract, and following up patients with history of transitional cell contrast in supine and upright positions were evalu- ated by consensus of 2 radiologists. Primary benefits carcinoma (2); it continues to be valuable in the follow-up evaluation of were improved filling and emptying of the collecting extracorporeal shock wave lithotripsy and endourologic therapy (e.g., system, and secondary benefits were nephroptosis Acucise endopyelotomy) (5). and ascertaining diagnosis of phlebolith. Radiologists have the responsibility of optimizing technical aspects RESULTS Of 170 patients, 337 kidneys and collecting systems of the urinary tract imaging, and they must be available for real-time (n = 168 right; n = 169 left) were examined. Im- monitoring of the examination for problem solving. For example, add- proved filling, emptying of the collecting system, ne- ing images obtained with gravity maneuvers, such as prone or depend- phroptosis, ascertaining diagnosis of phleboliths were detected with the rates of 12.5%, 44.2%, 8.3%, and ent oblique positioning, often assists in visualization of unopacified por- 3.2%, respectively. Improved filling was significant tions by improved filling of the ureters, especially in cases of obstruction in the presence of hydronephrosis (P < 0.05) and (1, 6). Upright positioning may be an alternative gravity maneuver for ureterolithiasis (P < 0.05) on both sides. There was a positive correlation between both improved filling improved filling. and presence of hydronephrosis, and improved fill- As humans spend most of their time in upright position in routine ing and presence of ureterolithiasis. Emptying was significant in collecting systems that had no visible daily life, the urinary system, like other systems, works in the upright pathology on IVU (P < 0.05) on either side. position most of the time. Therefore, it is reasonable to expect that up- CONCLUSION right radiographs reflect the real physiologic status of urinary system Upright KUB radiographs provide supplementary better than supine radiographs in IVU. The aim of this prospective study data about urine flow in terms of improved filling and was to assess the diagnostic benefit of taking a kidney-ureter-bladder emptying of the collecting system. (KUB) radiograph in an upright position during routine IVU. Key words: • urography • radiography • diagnosis Materials and methods Between February 2005 and September 2007, a total of 208 patients were referred for IVU exam. All patients were considered for inclusion in this study. Exclusion criteria were inability to stand because of hemi- paresis, early postoperative status, or cognitive inability to cooperate (n = 4); follow-up rather than initial IVU examination (n = 20); and el- evated blood urea level and serum creatinine (n = 14). The remaining 170 patients were included in the study. Indications for IVU requests are From the Departments of Radiology (K.G. kamilgurel@hotmail. given in Table 1. This study was approved by our institutional review com, S.G., M.K., Ö.Y.), and Urology (A.M.), Abant İzzet Baysal University, İzzet Baysal School of Medicine, Bolu, Turkey. board, and informed consent was obtained from all patients. The patients underwent bowel preparation on the day prior to the Received 5 February 2008; revision requested 13 April 2008; revision received 6 May 2008; accepted 11 May 2008. study; this consisted of 2 × 75 mg sennoside suspension taken at 7 p.m. 205 and 8 p.m. The patients were instructed after the 15th-min supine KUB radio- 2) Emptying of collecting system: to consume only fluids after 7 p.m. that graph. The 15th minute was chosen This was described as a reduction day and on the morning of the IVU. for upright KUB radiograph because it in the density of contrast material After the pre-contrast KUB was evalu- coincides with sufficient opacification from the collecting system and/or ated, 1 mL/kg of non-ionic contrast to visualize the pelvicalyceal system, reduction in the collecting sys- material, which included 300 mgI/mL, ureters, and bladder. Supine KUB ra- tem’s luminal caliber for upright was administered to the patient. diographs were obtained with 65−75 positioning. In our department, each step of a kVp, high milliampere, and short ex- 3) Nephroptosis: This is the down- standard IVU exam is performed un- posure time. All parameters were kept ward displacement of the kidney der the control and guidance of the ra- constant except the milliamperes, by ≥5 cm for an upright KUB ra- diologist. A basal standard IVU exam which were increased by about 5–10 diograph (asymptomatic neph- consists of 5 radiographs: pre-contrast mAs for upright KUB. Two reviewers roptosis) (7). Distance from the supine KUB, post-contrast supine with 7 years of experience with IVU iliac crest to the lower pole of KUB at the 7th and 15th minutes, su- analyzed the 15th-min upright KUB; the kidney was measured in both pine pelvic radiographs for full blad- they then compared their findings, supine and upright 15th-min ra- der, and supine post-voiding KUB. If generating a consensus interpretation. diographs, and any displacement any part of the collecting system is The following findings were noted as of the kidney ≥5 cm was noted invisible or poorly visualized, then diagnostic benefits: as nephroptosis. When delayed additional prone, compression, com- 1) Improved filling of collecting sys- excretion and hydronephrosis oc- pression release, and/or oblique ra- tem: This was described as better curred with upright positioning, diographs are taken until all parts are delineation and visualization of it was considered as pathologic well documented. For all the patients the collecting system, either whole nephroptosis. included in this study, an additional or partial, because of opacification 4) Phleboliths are differentiated from post-contrast 15th-min upright KUB on upright radiograph compared calculi by their oval shape and ra- radiograph was obtained immediately with the supine radiograph. diolucent center. If disappearance of superpositioning of phleboliths from the lower part of the ureters was seen in upright KUB radio- Table 1. Indications for intravenous urography requests graphs, this was noted as a second- ary diagnostic benefit. Indications Number of patients Improved filling and emptying were Urolithiasis 81 categorized as primary benefits, and detection of nephroptosis and bet- Collecting system dilatation on ultrasonography 27 ter differentiation of phleboliths were Flank pain 17 categorized as secondary radiological benefits. Urinary tract infection 9 Statistical analysis was performed Renal cyst 5 using the Statistical Package for Social Sciences (SPSS Inc., Chicago, Illinois, UP-UV stenosis 5 USA), version 11.0 software for Win- Urinary anomaly 5 dows. Descriptive statistics were gen- erated, and quantitative values were Incontinence 4 calculated using the chi-square test. Bladder tumor 3 Correlations between parameters were assessed using the Spearman correla- Hematuria 2 tion test. P < 0.05 was considered sta- tistically significant in all cases. Prostatism, BPH 2 Non-functioning kidney 1 Results In all, 337 kidneys and collecting sys- Pelvic pain 1 tems (nright = 168; nleft = 169) from 170 Previous urinary surgery 2 patients (82 men, 88 women; mean age, 46.48 ± 16.98 years) were included Renal tumor 1 in the study. One non-functional and Ureterocele 1 two agenetic kidneys were excluded. There were 5 (n = 2, n = 2, n Renal sinus lipomatosis on ultrasonography 1 right left bilat- eral = 1) duplicated collecting systems Bladder diverticula 1 (complete duplication, 2; incomplete duplication, 3), which were accepted